Process for the manufacture of calcium salts of inositol-phosphoric acid



Patented Oct. 4, 1927;

UNITED STATES PATENT OFFICE.

ALPEON S GAMS AND MAX GIRARD, F BASEL, SWITZERLAND, ASSIGNORS TO SOCIETY OF CHEMICAL INDUSTRY IN BASLE, 0F BASEL, SWITZERLAND.

PROCESS FOR THE MANUFACTURE OF GALCIUM SALTS 0F TNOSITOL-PHOSPHORIC ACID.

No Drawing. Original application filed April 9, 1923, Serial No. 630,913, and in Great Britain March 29, 1923. Divided and this application filed December 1, 1925. Serial No. 72,580.

The present application, which is a divi sion of our application Serial No. 630,913, filed April 9, 1923, relates'to a process for the manufacture of calcium salts of inositolphosphoric acid and comprises the process of making these calcium salts of,inos1tolphosphoric acid.

It is known that alkali metal salts of inositol-phosphoric acid may be obtained by treatment of the iron salt of this acid with alkali metal hydroxide. The iron salt of inositol-phosphoric acid itself had to be prepared from other salt mixtures of inositol-phosphoric acid, e. g. from a raw mixture of the calcium or magnesium salt by precipitating their solutions with an iron compound, e. g. iron chloride. I

It is further known that alkali metal salts of inositol-phosphoricacid may be trans- 2 formed, by double decomposition with calcium compounds, into saturated calcium salts of inositol-phosphoric acid of the formula From these the acid calcium salts of inositolphosphoric acid could be obtained according to a known method by addition of acid and precipitation by means of alcohol.

By a saturated salt of inositol phosphoric 80 acid a compound is understood wherein all the twelve hydrogen atoms of the phosphoric acid groups are replaced by a metal or an equivalent radical, for instance Ca, Mg, Na, NH and the lik 86- We have found, that alkali metal salts of inositol-phos horic acide may also be obtained direct y from the magnesium salts of this acid by treating them with an alkali metal hydroxide. a

By the rational combination of this new process of preparing the alkali metal salts of inositol-phosphoric acid with the aforesaid method of transforming an alkali metal salt of inositol-phosphoric into a calcium salt of this acid, it is possible to obtain acid calcium salts of inositol-phosphoric acid through the alkali metal salts by a simplified method, i. e. by avoiding the passa e through the iron salt of the inositol-phosp oric acid,

and, if desired, also the passage through the saturated calcium salts.

One may e. g. proceed as follows: A saturated or acid magnesium salt of inositol-phosphoric acid is boiled with an alkali metal hydroxide solution, whereby the saturated alkali metal salt of inositol-phosphoric acid, containing 12 atoms of alkali metal, is formed. The solution of the latter is mixed with somewhat more of a suitable acid than is necessary to form the acid alkali metal salt of inositol-phosphoric acid. To this solution there isadded a quantity of a soluble calcium compound necessary for forming the acid calcium compoundcof inositol-phosphoric acid, and the solution of the acid calcium salt of inositol-phosphoric is precipitated by means of alcohol. is

Instead of converting the alkali. metal salt of inositol-phosphoric acid directly into its acid calcium salt one may also first precipi- -tate the saturated calcium salt'of inositolphosphoric acid from the solution of the alkali ,metal salt by means of a calcium comversion into the calcium salt by precipitation with alcohol or by crystallization. Be-

fore isolation, the saturated alkali metal salt may be neutralized partially, the isolated alkali metal salt is then dissolved in water and further worked up to the soluble acid calcium salt, in the manner already described;

It will be obvious that the ambit of this invention is not limited to the reactions described above andparticularly detailed in the examples. The invention covers all forms-of theprocess which, starting from any niaglnesium or alkali metal'salt, use, on the one and, the double decomposition of a magnesium 'salt to an alkali metal salt and of an alkali metal saltto a calcium salt, and

on the other hand, the acohol precipitation producing directly or indirectly an acid calcium salt of inositol-phosphoric acid. The following examples il Ew'a'mple 1.

5 kilos of crude insoluble magnesium salt ustrate the invention.

will be described in the next examples.

- 4-5 litres of water, as it may e.

Emwmple 2.

The solution of '1 kilo of the saturate sodium salt of inositol-phosphoric aid in o tained accordin to Example 1, is mixed with hydrochloric acid until acid to Congo. This solution is mixed with 800 cc. of calcium chloride solution of 25 per cent. strength, and 1-2 times its volume of alcohol is added to dproduce a precipitate which is washed an dried. The ure white water-soluble powder thus obtained contains when dry 22.07 per cent. of phosphorus and 13.78 per cent. of calcium.

Example 3. The aqueous filtrate of the saturated sodium salt of inositol-phosphoric acid, obtained according to example 1, is mixed with calcium chloride solution or milk of lime until no more precipitate is produced. The precipitate is filter-pressed, well washed with water suspended in water, and dissolved by addition of h drochloric acid until acidity to Congo is indicated. The addition of-alcohol to this solution produces a precipitate which is well washed and dried in a vacuum. The pure white water-soluble powder thus obtained contains 21.61 per cent.

v of phosphorus and 13.48 per cent. of calcium.

Example 4.

scqpic powder very easily soluble in water an is the neutral sodium salt -'of inositolphosphoric acid. This compound may be converted into the acid calcium salt of inositol-fihosphoric acid in the manner described in xample 2 or 3.

Example 5.

The aqueous solution of the saturated sodium salt of inositolhosphoric acid obtaineil as described in xam le 1 is mixed with alcohol, the precipitate is filtered with pressure, washed with alcohol, and dried. It constitutes the saturated sodium salt containing water of crystallization. It disein.

In converting this salt into the acid calcium. salt, the method of Example 2 or 3 may be used.

Ewaxmple 6.

The solution of the saturated sodium salt of inositol-phosphoric acid, obtained as described in Example 1, is concentrated on the water bath until a sample shows a crystalline separation after standing in the cold. This crystalline product is then recrystallized in the cold, whereby white colourless crystals are obtained, which are easily .soluble in water to a solution having alkaline reaction. By further concentration of the mother liquor, or by precipitation with alcohol, an

additional quantity of the sodium salt containing water of crystallization can be obtained.

The salt thus obtained may be converted into the acid calcium salt according to Example 2 or3.

What we claim is:

1. The herein described manufacture of calcium salts of -inositol-phosphoric acid consisting in treatin compounds of inositolphosphoric acid of t e formula G H ZT G (wherein the 12 hydrogen atoms represented by X are substituted wholly or partially by magnesium) with alkali metal hydroxides and converting the alkali metal salts of inositel-phosphoric acid thus obtained with calcium compounds of sufiicient solubility in the medium wherein the reaction is efifected, and whose anion yields with sodium a salt soluble in dilute alcohol.

2. The herein described manufacture of acid calcium salts of inositol-phosphorie acid consisting in treating compounds of inositol-phosphoric acid of the formula (wherein the 12 hydrogen atoms represented by X are substituted wholly or partially by magnesium) with alkali metal hydroxides an converting the alkali metal salts of inositel-phosphoric acid thus obtained under acid conditions with calcium compounds soluble in the reaction medium, whose anion yields with sodium a-salt soluble in dilute alcohol. 3. The herein described manufacture of acid calcium salts of inositol-phosphoric acid consisting in treating compounds of inosltol-phosphoric acid of the formula Q H O RX (wherein the 12'hydrogen atoms represented by X are substituted wholly or partially by ma esium) with alkali metal h droxi es, 5 tering the mixture, mixing t e filcium salt of inositol-phosphoric acid thus.

obtained with alcohol.

4. The herein described manufacture of acid calcium salts of inositol-phosphoric acid, consisting in treating compounds of inositol-phosphoric acid of the formula G R M G (wherein the 12 hydrogen atoms represented by X are substituted wholly or partially fliily magnesium) with caustic soda solution, tering the mixture, mixing the filtrate containing the saturated sodium salt of inositolphosphoric acid with somewhat more-of an acid yielding with the alkali metal a salt soluble in dilute alcohol, than is necessary to form the acid sodium salt of the inositolphosphoric acid, adding to this solution a calcium compound, soluble in the reaction medium, whose anlon yields with sodium a salt soluble in dilute alcohol, employing a quantity of the calcium compound equivalent to the acid sodium salt of the inositolphosphoric acid present, and precipitating the solution of the acid calcium salt of the inositol-phosphoric acid thus obtained with alcohol.

5. The herein described manufacture of acid calcium salts of inositol-phosphoric acld, consisting in treating compounds of in ositol-phosphoric acid of the formula (wherein the 12 hydrogen atoms represented by X are substituted wholly or partially by magnesium) with caustic soda solution at temperatures up to the boiling point of the latter, filtering the mixture, mixing the filtrate containing the saturated sodium salt of inositol-phosphoric acidwith somewhat more of an acid, yielding with the alkali metal a salt soluble in dilute alcohol, than is necessary to form the acid sodium salt of the inositol-phosphoric acid, adding to this solution a calcium compound, soluble in the reaction medium, whose anion yields with sodium a salt soluble in'dilute alcohol, employin a quantity of" the calcium com ound equiva ent to-the acid sodium salt of t e inositol-phosphoric a'cid present and-preciph tating the solution of the acid calcium salt of inositol-phosphoric acid thus obtained with alcohol.

6. In the manufacture of acid calcium salts of inositol-phosphoric acid from its magnesium salts, the etc of converting the magnesium salts of inositol-phosphoric acid into its saturated alkali meta salts by direct conversion with alkali metal hydroxides.

In witness whereof we have hereunto signed our names this 19th day [of November ALPHONS' GAMS. MAX GIRARD. 

